Antimicrobial Properties of Honey †Free Samples to Students

Question: Discuss about the Antimicrobial Properties of Honey. Answer: Introduction Honey is prepared by the worker honey bees by collecting the nectar of flowers and it contains sugars and amino acids besides several other substances fluid that may be yellow, brown or golden in colour. It has been used as a topical antimicrobial for wound healing in traditional medicine. Monofloral honey is made of nectar collected from one flower and polyfloral honey is made from nectar collected from many species of flowers. The antimicrobial properties of honey have been studied as part of several in vitro and clinical studies (Israili, 2014). Due to the problem of antibiotic resistance among bacteria, the antimicrobial effect of honey against bacteria that exhibit resistance to antibiotics, specifically, Staphylococcus aureus that exhibits methicillin resistance, has generated a lot of interest(Dixon, 2003). Antimicrobial activity of honey has also been observed against Streptococcus pyogenes and S. pneumoniae that is known to cause pneumonia, meningitis and middle ear infectio ns among humans. Honey has been proven to be an effective treatment when applied topically to infected wounds in vivo (Huttunen, Riihinen, Kauhanen, Tikkanen-Kaukanen, 2013). The antimicrobial action of honey can be attributed to its due to the high sugar content and to the presence of the oxidising compound, hydrogen peroxide. The low pH of honey also contributes in killing bacteria. Antimicrobial peptide, the bee defensin-1 plays a role in containing bacteria. Phenolic compounds present in honey reduce the count of microbial flora on topical application of honey. Manuka honeys and Revamil are honeys that have been used in wound management in clinical settings. At concentrations of 40% and 60% honey has been found to have high antimicrobial activity. Honey has been traditionally added to hot drinks and this provides topical application of honey in the nasopharyngeal region and stops the growth of pathogens that colonize the region, S. aureus, S. pneumoniae and S. pyogenes, tht usually cause respiratory infections (Huttunen, Riihinen, Kauhanen, Tikkanen-Kaukanen, 2013). Apart from antimicrobial properties honey also has anti-inflammatory and immune modulating properties(Israili, 2014). The fact that honey is produced by different varieties of bees using nectar from different species of flowers means that its composition also varies considerably. This poses a problem for researchers because when using honey from different sources the results may not always be reproducible. Manuka honey, is a monofloral type of honey that produced by honey bees that collect nectar exclusively from the flowers of the Leptospermum plant that is native to New Zealand. It is used for medicinal use and studies. The plant is also commonly seen in Australia. The product is recognised by medical regulatory bodies as a registered wound care product (Carter, et al., 2016). Antibiotic resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Escherichia coli (that produces beta lactamase) , Pseudomonas aeruginosa (that has ciprofloxacin resistance) were susceptible to killing with10-20% concentration of honey. The hydrogen peroxide and methylglyoxal content of honey was neutralised using enzymes to check honey for antimicrobial activity without these two compounds. The activity could be attributed to the presence of bee defensin-1. When pH of honey was changed from 3.3 to a neutral pH 7.0, the remaining antimicrobial activity could be due to the high sugar concentration (Kwakman, et al., 2010). When used for wound dressing, honey not only acts as an antimicrobial but also reduces scarring (Biglari, et al., 2013). A novel compound, leptosin enhances the antimicrobial properties of Manuka honey. Its detection is employed as a biochemical marker for identification of whether the honey is made from Leptospermum nectar (Kato, et al., 2012). An important aspect of the antimicrobial activity is that it can kill bacteria that form and live in biofilms. The extracellular matrix of bacterial biofilms is usually found on surfaces of teeth, implants and mucosal surfaces and provides protection to bacteria from many antibacterial agents. But bacterial aggregates of biofilms can be disrupted by Manuka honey. It is even effective against biofilms formed by mutiple species. The methylglyoxal content of honey is usually responsible for disruption of biofilms. Conclusion In conclusion, there is evidence that honey can kill bacteria that have become resistant to antibiotics. Multidrug resistant bacteria are a problem as known antibiotics cannot kill these pathogens. The antibiotic activity of honey can be attributed to high concentration of sugar, presence of hydrogen peroxide, bee defensin-1, a peptide found in honey and methylglyoxal. The low pH of honey also contributes to its antibacterial activity. Topical application of honey is effective in treating wound infections. It is interesting to note that Manuka honey that is largely found in Australia and New Zealand and is effective against biofilm forming bacterial species. Usually bacteria that form biofilms are more difficult to treat and antibiotic treatments do not affect them. References Biglari, B., Moghaddam, A., Santos, K., Blaser, G., Bchler, A., Jansen, G., . . . Simon, A. (2013). Multicentre prospective observational study on professional wound care using honey (Medihoney). International Wound Journal, 10(3):252-9. Carter, D. A., Blair, S. E., Cokcetin, N. N., Bouzo, D., Brooks, P., Schothauer, R., Harry, E. J. (2016). Therapeutic Manuka Honey: No Longer So Alternative. Frontiers in Microbiology, 7, 569. https://doi.org/10.3389/fmicb.2016.00569. Dixon, B. (2003). Bacteria can't resist honey. The Lancet, Infectious Diseases, 3(2):116. Huttunen, S., Riihinen, K., Kauhanen, J., Tikkanen-Kaukanen, C. (2013). Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria. APMIS, 121(9): 827834. Israili, Z. (2014). Antimicrobial properties of honey. American Journal of Therpeutics, 21(4):304-23. Kato, Y., Umeda, N., Maeda, A., Matsumoto, D., Kitamoto, N., Kikuzaki, H. (2012). Identification of a novel glycoside, leptosin, as a chemical marker of manuka honey. Journal of Agriculture and Food Chemistry, 60(13):3418-23. Kwakman, P., te Velde, A., de Boer, L., Speijer, D., Vandenbroucke-Grauls, C., Zaat, S. (2010). How honey kills bacteria. FASEB Journal, 24(7):2576-82.